1. Field of the Invention
The present invention is related to a multilayer printed wiring board with a built-in low-thermal-expansion substrate; especially to a multilayer printed wiring board preferred to be used as a packaging substrate for mounting an IC chip.
2. Discussion of the Background
Japanese Laid-Open Patent Publication 2001-102479 describes an interposer which electrically connects an IC chip and a packaging substrate. Interposer body 20 in FIG. 2 is made of silicon, via conductors 27 penetrating the silicon are connected to the electrodes of an IC chip, and a wiring layer is formed on the surface of the silicon substrate opposite the IC chip. The contents of this publication are incorporated herein by reference in their entirety.